A key frame defines a segment of the PointAnimationUsingKeyFrames to which it belongs. Each key frame has a target Value and a KeyTime. The KeyTime specifies the time at which the key frame's Value should be reached. A key frame animates from the target value of the previous key frame to its own target value. It starts when the previous key frame ends and ends when its own key time is reached.

Spline key frames like SplinePointKeyFrame create a variable transition between values, which is determined by the KeySpline property. Splined interpolation can be used to achieve more realistic "real world" timing effects such as acceleration and deceleration.

This example shows how to use the PointAnimationUsingKeyFrames class to animate a Point.

The following example moves an ellipse along a triangular path. The example uses the PointAnimationUsingKeyFrames class to animate the Center property of an EllipseGeometry. This animation uses three key frames in the following manner:

During the first half second, uses an instance of the LinearPointKeyFrame class to move the ellipse along a path at a steady rate from its starting position. Linear key frames like LinearPointKeyFrame create a smooth linear interpolation between values.

During the end of the next half second, uses an instance of the DiscretePointKeyFrame class to suddenly move the ellipse along the path to the next position. Discrete key frames like DiscretePointKeyFrame create sudden jumps between values.

During the final two seconds, uses an instance of the SplinePointKeyFrame class to move the ellipse back to its starting position. Spline key frames like SplinePointKeyFrame create a variable transition between values according to the values of the KeySpline property. In this example, the animation begins slowly and speeds up exponentially toward the end of the time segment.

<Pagexmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"Background="White"Margin="20"><CanvasWidth="400"Height="400"><PathFill="Blue"><Path.Data><!-- Describes an ellipse. --><EllipseGeometryx:Name="MyAnimatedEllipseGeometry"Center="200,100"RadiusX="15"RadiusY="15"/></Path.Data><Path.Triggers><EventTriggerRoutedEvent="Path.Loaded"><BeginStoryboard><Storyboard><!-- Animating the Center property uses 3 KeyFrames, which animate
the ellipse allong a triangular path. --><PointAnimationUsingKeyFramesStoryboard.TargetProperty="Center"Storyboard.TargetName="MyAnimatedEllipseGeometry"Duration="0:0:5"RepeatBehavior="Forever"><!-- Over the first half second, Using a LinearPointKeyFrame, the ellipse
moves steadily from its starting position along the first line of the
trianglar path. --><LinearPointKeyFrameKeyTime="0:0:0.5"Value="100,300"/><!-- Using a DiscretePointKeyFrame, the ellipse suddenly changes position
after the first second of the animation. --><DiscretePointKeyFrameKeyTime="0:0:1"Value="400,300"/><!-- Using a SplinePointKeyFrame, the ellipse moves back to its starting
position. It moves slowly at first and then speeds up. This key frame
takes 2 seconds to complete. --><SplinePointKeyFrameKeySpline="0.6,0.0 0.9,0.00"KeyTime="0:0:3"Value="200,100"/></PointAnimationUsingKeyFrames></Storyboard></BeginStoryboard></EventTrigger></Path.Triggers></Path></Canvas></Page>